Understanding the Different Types of RFID Tags

There are primarily three basic types of RFID tags that are familiar to most consumers who use the technology: active, passive, and semi-passive. When considering purchase of tags for different scenarios, pinpointing which kind of tag to use and integrate into an operation can be tricky. So let’s compare using some facts and a few examples knowing full well that, in many cases, the individual situation and the pocketbook often make the decision on which tag goes into what operation.

RFID TAG Similarities

Passive/Active Tags

allow wave penetration that eliminates line of sight transmission.

use Radio Frequency (RF) electromagnetic energy.

enable readers to detect and identify objects.

are amenable to large-scale applications such as GPS and sensor technology.

can monitor and record sensor data: time, temperature, pressure, etc., but only active tags are continuously monitoring and recording.

bear data that can be manipulated or static: read-write, read-only, and WORM (“write once, read many”).

enable “simultaneous reads” through anti-collision algorithms of entire fields since radio frequency waves penetrate most objects.

can, in snapshot fashion, monitor and record sensor data: time, temperature, pressure, etc

are inexpensive with costs trending down (approximately $.05 and up in quantity).

experience some read failure with low energy reads.

are often read with hand-held readers, but readers can also be fix mounted.

are usually attached to commonplace items that are made to be disposable.

need little or no maintenance.

Semi-Passive RFID Tags

are battery-powered.

do not transmit active signals.

can monitor things in a container, such as climate or security breaches.

range from $10 to $50 in price.

Transportation venues, military and civilian, have benefited from active tags for years in gateway security and collection of tolls and fees. Freight companies use them for similar reasons. School districts are now using GPS plus active RFID tags to manage their fleets of busses to be spot on for efficiency and child welfare.

But active RFID tagging goes further than fleet management. As early as 2004, Merrimac Industries, Inc, a maker of microwave parts used active RFID tags to track propriety folders throughout their 50,000 square-foot facility, according to Axcess. Merrimac implemented the RFID system to rapidly deliver customer quotes. Similar applications abound with the insight to create them in a hospital/pharmaceutical situations perhaps.

Through item level tracking, inventory control and supply chain management, retail marketing and high volume manufacturing have histories of using passive tags successfully in WIP. But no history is longer than the effective use of passive tags in agricultural animal tagging. Libraries too were early adaptors of the technology to keep a stable inventory of media. During wartime, the wounded have been and are identified and treated with the help of passive RFID tags sewn into their military attire.

Semi-active tags have made their mark in the identification of container tampering and tracking of high valued merchandise.

Conclusion

So, when buying RFID tags what is really important to know? First you need to understand the different types of RFID tags and their basic functions, but, more importantly, they want you to know that tags and their uses vary. In some ways,variation is the essence of this emerging technology.

Applications may have different or similar uses for tags: one is successful using active tags, one using passive tags, and the third using semi-passive tags. The versatility of the tags and the imagination of the client certainly can be the deciding factor in which tag to use in an operation--but it helps to have the professional guidance of a RFID converter like Metalcraft who listens and can help find the right solution.